Where is the North Star today?
According to Scientific American: "The North Star, or Polaris, is the brightest star in the constellation Ursa Minor, the little bear (also known as the Little Dipper)."
Click on the link to the right for their full article (with a picture showing the location).
Because Polaris lies nearly in a direct line with the axis of the Earth's rotation "above" the North Pole - the north celestial pole - Polaris stands almost motionless on the sky, and all the stars of the Northern sky appear to rotate around it. Therefore, it makes an excellent fixed point from which to draw measurements for celestial navigation and for astrometry.
The web site in the related links also shows the direction of Polaris relative to Earth in the galaxy.
North star is the polar star, not the pole star. The North Star is the pole star; it is diredtly above the North pole and is called Polaris. A polar star is a star in close proximity to the polar region such as Sigma Octantis, the Southern star which is close to but not directly over the South pole.
The usage of the north star, or Polaris, is to find which way you are facing. If you are facing in the direction of it, you are facing north. If you are facing the opposite direction of the north star, you are facing south. If you are facing left of the north star, you are facing east. If you are facing right of the north star, you are facing west.